Method of producing a rolling hoop formation in the shell of a sheet metal drum



y 5, 1966 A. H. CAMPBELL ,0

METHOD OF PRODUCING A ROLLING HOOP FORMATION IN THE SHELL OF A SHEET METAL DRUM Filed March 28, 1963 5 Sheets-Sheet 1 FIG. 1

INVENTOR Andrew H. Campbell ATTORNEYS y 5, 1966 A. H. CAMPBELL 3,259,091

METHOD OF PRODUCING A ROLLING HOOP FORMATION IN THE SHELL OF A SHEET METAL DRUM Filed March 28, 1963 3 Sheets-Sheet 2 INVENTOR Angew H.Cumpbell TORNEYS A. H. CAMPBELL July 5, 1966 3,259,091

METHOD OF PRODUCING A ROLLING HOOP FORMATION IN THE SHELL OF A SHEET METAL DRUM 3 Sheets-Sheet 3 Filed March 28, 1963 INVENTO'R Andrew H.Compbell ATTORNEYS United States Patent 1ce METHOD OF PRODUCING A ROLLING HOOP gORMATION IN THE SHELL OF A SHEET METAL RUM Andrew H. Campbell, Elizabeth, N.J., assignor, by mesne assignments, to American Light Gage Drum Corporation, New York, N.Y., a corporation of New York Filed Mar. 28, 1963, Ser. No. 268,721 1 Claim. (Cl. 113-120) This invention relates to improvements in metal shipping containers and more particularly to drums made of sheet metal having intermediate the ends of the drum rolling hoops or rings each having a concave face, the invention being directed to an improved method of producing such drums.

The invention relates to an improved method of producing a rolling hoop formation which consists of vtwo similar, narrow, circular ribs of the same diameter spaced apart somewhat from each other and having between them a circular pocket which has a concave bottom surface, the two ri'bs being spaced an appropriate distance apart and projecting an appropriate distance from the cylindrical surface of the drum to form a rolling hoop. At least one rolling hoop consisting of such a pair of ribs with a concave surface therebetween is located at a fixed distance from each end of the drum. Advantageously, two, three or more such rolling hoop formations are provided in lightweight drums 'in the upper half thereof and similarly in the lower half.

In accordance with the invention the method of producing a rolling hoop formation in the shell or cylindrical portion of a sheet metal drum comprises the forcing of the metal of the shell outwardly simultaneously at all points of the periphery of the shell and at two restricted areas in the lengthwise direction of the shell, such areas being spaced apart corresponding to the width of the rolling hoop desired, and forming during such forcing action a concave depression or recess between the two restricted areas.

The invention will be further described in connection with the accompanying drawings but it will be understood that the invention is not limited thereto.

In these drawings:

FIG. 1 is a view in side elevation of a lightweight, light gauge metal drum having four rolling hoop formations in its shell or cylindrical side wall;

FIG. 2 is a detailed vertical section taken on line 22 of FIG. 1 and drawn to an enlarged scale to illustrate the shape of the improved rolling hoop formation in a drum of 24-gauge sheet metal;

FIG. 3 is a view similar to FIG. 2 but showing the formation in a shell made of 22 -gauge sheet metal;

FIG. 4 is a perspective view of a drum load consisting of a group of four drums secured together by flat-band sheet strapping of standard dimensions;

FIG. 5 is a detailed vertical section taken on line 5-5 of FIG. 4;

FIG. 6 is a detailed vertical section showing the internesting of a standard rounded conical rolling hoop with a rolling hoop of the present invention;

FIG. 7 is a view showing in vertical section one form of tool which may be used in producing the rolling hoop formation of the invention.

FIG. 8 is a view partly in elevation and partly in section showing diagrammatically a machine having tools 3,259,091 Patented July 5, 1966 according to FIG. 7 for simultaneously forming two rolling hoop formations in a sheet metal drum; and

FIG. 9 is a fragmentary view in transverse section taken of broken line 9-9 of FIG. 8.

Referring now to these drawings and first to FIGS. 1, 2 and 3, the drum 20 of light gauge sheet metal has a shell or cylindrical portion 21 and heads closing the top 22 and bottom 23 of the shell, these heads being secured in position by chimes 24 and 25 of any appropriate construction. In the top head 22 of the drum there is the usual filling opening 26 (FIG. 4).

In the cylindrical portion of shell 21 two rolling hoops 27 and 28 are arranged between the mid-portion of the shell and the top 22, these rolling hoops being spaced apart from one another and also spaced from the head 22 according to the standards of the shipping container industry. Likewise, rolling hoops 29 and 30 are arranged in the lower portion of shell 21 and at corresponding relative distances from the bottom 23. It will be understood, however, that the number of rolling hoops employed can be varied as desired and will depend upon the use to which the drum containers are to be put, and the gauge thickness of the metal used for the shell.

Certain standard sizes of drum containers have been adopted by the steel container industry holding, for example, gallons and 30 gallons respectively. The 55- gallon drum is approximately 23" in diameter and approximately 35 in height. These are the drum containers contemplated by the invention and the shell or cylindrical portions may be made of light gauge steel, such for example as 24-gauge or 22-gauge for the 55-gallon drums and even thinner gauge of steel for the 30-gallon drums. The drum may also be made of heavier gauge steel, such as SS-gallon metal containers of 18- or 16 or l4-gauge.

Referring now to FIGS. 2 and 3, these two figures show representative examples of the improved rolling hoop formations in 24-gauge and 22-gauge drums respectively. The formations constituting the rolling hoops 27-30 comprise two similar, narrow, circular ribs, ridges or beads 31 and 32 of the same diameter and spaced somewhat apart from each other as shown, these two ribs having between them a circular channel, recess or pocket 33 having a concave surface. The narrow character of ribs 31 and 32 is indicated by the fact that the radius of curvature of the innersurface of the shell opposite these ribs is advantage ously of the order of A. The outside boundaries of circular ribs 31 and 32 are located outwardly from the surface of shell 21 a sufiicient distance to support the shell in rolling engagement with a flat surface and with the chimes 24 and 2-5 out of contact with such surface. As indicated, has been found advantageous for this dimension. The improved rolling hoop formation, in all respects, meets the specifications of the industry.

With the ribs 31 and 32 spaced somewhat more than one inch apart, not only do the ribs perform their rolling hoop functions, but also a channel or pocket 33 is formed which has sufficient depth to receive a flat-band metal strap 34 as shown in FIGS. 4 and 5. Such flat-band metal .strap is of dimensions which have been found by the Association of American Railroads to be appropriate for binding or holding together a group of the drum containers for shipment by railroad car, and this strap 34 fits within the pocket 33 with its outer surface not extending beyond the peripheries of the ribs 31 and 32. The pocket serves to prevent the metal strap 34 from shifting either upwardly or downwardly on the surface of the drum. Such shifting presents a problem with containers not provided with the improved rolling hoop formation.

In FIG. 4 there is shown a group of four drum containers 20 which have been assembled upon a platform or pallet 35. These drums are secured together by means of the upper and lower horizontal fiat-band straps 34 and also by vertical strapping 36 which is attached to pallet 35 in any suitable manner and extends over the rigid cross members 37 and 38 on top of the four drums. All of this strapping is tensioned and sealed so that the drums are firmly secured in position. Staples 39 prevent strapping 36 from becoming disengaged from cross members 37 and 38. Also staples 40 in the vertical wood stay 41 assist in holding straps 34 in place. Pallet 35 with its drum load may then be placed in a truck or rail car.

By placing the improved rolling hoop formations at the accepted standard locations throughout the height of the drum intermediate its ends, drums having the rounded conical type of rolling hoop may be intermixed in a unit with drums having the rolling hoop formations of the invention. When this is done, as shown in FIG. 6, the conical rolling hoop formation 43 on a drum 42, for example, will be received within the recess 33 between the circular ribs 31 and 32 of the improved rolling hoop formation on an adjacent drum 20. This produces an interlocking of the two drums and the flat-band strapping 34, if used, will hold the unit in condition of maximum load solidarity.

The forming of the rolling hoops in the cylindrical sheet metal shell of the drum, as is customary, should be done subsequent to the welding of the side seam of the shell and prior to the assembly of the shell 21 to the top and bottom head members 22 and 23. The shell is usually formed with end flanges after the welding of the side seam, and it is advantageous to form the rolling hoops after the completion of the shell flanging operation.

Referring to FIGS. 7-9, the method comprises the forcing of the metal of shell 21 (FIG. 8) outwardly simultaneously at all points of the periphery of the shell and at two restricted areas such as indicated by ribs 31 and 32, these areas being spaced apart to correspond with the width of the rolling hoop desired, forming during such forcing action the concave depression, channel or pocket 33 between the .two restricted areas and extending continuously throughout the circumference of the shell.

, One way of carrying out this method is by means of a tool such as indicated at 49 in FIGS. 7, 8 and 9. This tool as shown in cross section in FIG. 7 has two similar narrow rib portions 50 and 51 interconnected by a concave surface 52. As shown in FIG. 9, tool 49 is sector shaped and corresponds in circular length to about A; of the circumference of drum 21. Eight of these sector shaped tools 49 are mounted on similarly shaped supports 53, being secured thereto by means of screws 54.

Supports 53 are in turn mounted upon the outer cylindrical surfaces of sector shaped members 55 to which they are secured by screws 56. The sector shaped members 55 are mounted by means not shown for radial movement with respect to a central shaft 57. Shaft 57 is movable lengthwise, also by means not shown, and has mounted upon it two octagonal cam members 58, the outer sloping surfaces 59 of which engage corresponding sloping surfaces on the inner faces of sector members 55.

Lengthwise movement of shaft 57 and octagonal earns 59 will produce simultaneous radially outward movement of sector members 55, supports 53 and sector shaped tools 49, causing these tools to engage the interior cylindrical surface of shell 21. Continuous simultaneous outward movement of the sector shaped tools 49 will cause their rib portions 50 and 51 to form the narrow spaced cylindrical rib-like formations 31 and 32 as indicated in FIG. 8, the pressure of these ribs 50 and 51 being uniform in all radial directions,

The apparatus shown in FIG. 8 is constructed to form two rolling hoop formations, for example formations 27' and 28 simultaneously, although they can be formed one at a time if desired. It will be understood that a stop (not shown) is provided for the one end of drum 21, and after the two formations 27 and 28 have been completed, drum 21 is removed from the apparatus and reapplied in the opposite lengthwise direction. Thereupon the remaining two rolling hoop formations 29 and 30 are formed. It will be further understood that if desired the apparatus can be constructed to form all four of the rolling hoop formations simultaneously.

It is understood that FIGS. 8 and 9 show diagrammatically a form of mechanism for imparting the radial movement to tool segments 49. In practice, apparatus such for example as disclosed in Grotnes Patent No. 2,089,476 may be used.

Referring to FIG. 7, as the ribs 50 and 51 are forced outwardly forming the circular ribs 31 and 32 in the metal of shell 21 the metal of the shell between the rib portions 54 and 51 is pulled outwardly but lags behind the metal which is in engagement with these ribs. The extent of this lag produces the depth of the circular concave channel or recess 33, and the depth of this recess is a function of the strength and pliability of the metal of shell 21 and is also proportional to the spacing of rib portions 50 and 51.

Although FIGS. 2 and 3 show representative examples of the shape of the rolling hoop formations, the form of the circular channel 33 may vary. For example, it will vary with the strength and pliability of the metal. Also, due to variation in the physical characteristics of different sheets of steel rolled out of the same ingot, the form of the channel may vary to some extent even between containers made of the same gauge metal. The form of the channel 33 is also a function of the metal thickness, as will be observed in comparing FIGS. 2 and 3. The same tool segments 49 shown in FIG. 7 may be used for drums made of 22-gauge metal as well as those made of 24- gauge. As previously explained, the tool segments 49 force the metal outwardly uniformly in all directions at the same time, and the operation is carried on until the tips of the ribs 31 and 32 are disposed the required distance radially outward from the shell surface, namely When the tool segments are backed away the metal of the shell springs back to a certainextent, and the amount of spring-back varies with the thickness with the metal, being greater with the 22-gauge metal than the 24, as indicated by the dimensions shown on FIGS. 2 and 3.

The bottom of concave channel 33 does not necessarily contact the bottom of concave surface or groove 52 in the tool segments 49. Consequently, except for the desirability of strengthening tool members 49 the formation of the tool between rib portions 50 and 51 could follow the dotted line 60. The lag in the metal above referred to has been found to produce a recess 33 of the desired depth, but should shallower recesses be desired, the concave surface 52 of tool 49 may be raised above the natural curvature of the metal as shown in FIG. 7, thereby limiting the lag of the metal as it is explained by the ribs 50 and 51.

I claim:

The method of producing in the shell of a sheet metal drum a rolling hoop formation having a concave face which comprises forcing the metal of the shell outwardly throughout the periphery of the shell at two restricted areas spaced apart corresponding to the width of the rolling hoop and forming two external circular ribs, thus producing a circular concave recess between the two areas, the depth of the concave recess below the tops 'of the ribs depending upon the strength and pliability of the metal of the shell and being proportional to the spacing of the ribs.

(References on following page) 5 6 References Cited by the Examiner 3,068,932 12/ 1962 cimochowski 15373 Schwartz 12/1ss9 Crary 220-72 FOREIGN PATENTS 3/1890 Stiveson 2 0 2 5 401,958 11/ 1933 Great Britain.

2/ 1894 Carter 220 761,517 11/ 1956 Great Britain.

8/1936 Rueppel 206-3 5/1946 Grodin 206-65 CHARLES W. LANHAM, Primary Examiner.

11/1957 Eugan T. E. COUDON, R. D. GRBFE, M. L. RICE,

6/1960 La Martine 15373 Examiners 

